Coking and deactivation behavior of ZSM-5 during the isomerization of styrene oxide to phenylacetaldehyde

Abstract Coking and deactivation behavior of ZSM-5 in the isomerization of styrene oxide to phenylacetaldehyde were investigated under gas-phase free of solvents. More soft coke was firstly formed on HZSM-5 and then partly converted to hard coke with the reaction carried through. The soft coke, which can be removed via desorption at 200–400 °C, had little effect on the catalyst activity and selectivity. While the hard coke, which had a certain degree of crystallization and must be completely removed via combustion with oxygen, would cause major catalyst deactivation. By confirmed, pore blocking was the predominant mode leading to deactivation of catalyst.